Superheater



H. B. OATLEY April 25, 1933.

SUPERHEATER Filed April 20, 1931 2 Sheets-Sheet l m. a NIJ Nu Q, a Nw mww Sv QN *N E n N\ f. NN Wr W N lx. nu QM. Nm, un @$5 NN April 25, 1933.H. B. OATLEY v 1,905,739

SUPERHEATER Filed April 20, 1931 2 Sheets-,Sheet 2 INVENTOR HenryB Oalley.

ATTORNEY HENRY 1B. OATLEY, OFGREAT Patented Apr. 25, 1933 UNITED STATESPATENT o NECK, NEwYoax, AssIGNoa 'ro :1HE PANY, or NEW Yoan, N. Y.

SUPERHEATER Apliiication med April 2o,

` MyY invention relates to i're-bo-x superheaters and more particularlyto superheaters installed in hre-boxes of locomotive type boilers.equipped with so-called arch tubes. The advantages' of radiant typesuper-` heaters have been recognized insofar as economy of spacei andmaterial arerconcerned, especially wherea high degree of'superheat isdesired, but it has proven difficult to pre* vent the units of radianttype superheaters from burning out. These `diflicultie's areparticularly serious in a locomotive type boiler where the ordinary rateof combustion per'unit volume is high.

`It' is an object of the present invention to provide a superheaterhaving, at least in part,radiant type characteristics, and adapted for`use in the combustion space of locomotive type boilers.

'n 4Further objectsand advantages of my invention will be clear tovthose skilled in the art from the following description of a givenembodiment of the'invention taken in p, connection with the accompanyingdrawings in which: Y

Fig. liis a vertical central `longitudinal section throughl a'rearportion of an arch type fire-box in a locomotive type boiler.

Fig. 2 is a half-section 'of a boiler illus-V trated in Fig. 1, takenonthe vline 2 2 and looking in the direction of the arrows.

Fig. 3 is a transversesection of the boiler illustrated inFig.'1,takenon the line 3--3 and looking in the direction of the arrows;

.. tubesare run from the water leg rearwardly and upwardly above thegrates or burners and connectedinto therear water leg.` Ordinarily, archbrick are supported on the lower andforward portions of the arch tubeslin such-locomotives so as to form a baffle. In accordance with myinvention, superheater 1931. serial No. 531,379.

elements are` run along the'uppersurface of the baffle formed by thearch bricks. f

'In Figs. 1, 2 and 3, I have illustrated aV locomotive rboiler 10 havingsmoke tubes 12,

a forward water leg 14, and a rear water leg 16, respectively, as thefront and-rear ends of the fire-box 17. l Extending rear-y" wardly andupwardly between the-water legs 14 and 16 and running above the gratesor burners are arch tubes 18, 18. Extendeo ing across the fire-box 17forward of the grate or burner space is a beam 20 above which is a firewall 22, preferably of vlire brick, and extending up to the plane ofthearch tubes 18. The vfuel is burned in the space 24 between the firewall22- and the rear face of the fire boxfin accordance with the commonpractice. On the arch tubes 18 are'arch brick 26, 26 which may be of anyusual or desired type. `rIhe fire wall l22 is 7o spaced rearwardly fromthe forward water leg 14 enoughto permit the insertion of the ends ofsuperheater units between-the wall and the water leg. In the arrangementshown, the means for leading steam t'o and 75 l from the superheate'r'units comprisesY a header 28 which extends transversely of the boiler 10just below the level of the beam 20 and between such beam and the waterleg 14. Superheater units '30, 30 are con-` 8K0 nected to the header 28and extend upwardly forward of the wall 22 and then rear-` wardly alongthe upper surface of the arch formed by the brick 26. Preferablyv `therear ends 32 of elements 30 are protected 85 from the scouring action ofthehot gases kin the fire-box by specialarch brick 34, 34,

the upper ends 34a of which are curved forwardly above the rear upperkends 32of the units 30. It will be seen that the units 30 not onlyreceive heat by radiation Vfrom. the combustion of'gases inthecombustion space above. the arch'but also receive a cer-l tain amountof heat'by direct contact with the gases and that the undersurfaces ofthe elements 30 receive heat by radiation direct-V ly through the firebrick 26. The heat absorption by units 30 is therefore quite high perunit area and the total area of these units .can be small in proportiontothe SUPERHEATER comziv amountl of superheat added by them to thesteam. However, to reduce the rate of depreciation of units 80, I preferthat they lie almost entirely below the level of the rear upper end ofthe arch brick 26, whereby the convection heat flow to units 30 is keptlow.

lVhile the rate ofvheat absorption bythe units 30 is high, in a greatmany cases it is not convenient to design the locomotive with Vlongfenough-lire-box'so that all the superheating surface can be placedabove ytheY arch. I have therefore illustrated in Fig.

l, besides the superheating surface in the elementsjatthe rear-of thetube sheet, I prefer tomake the-header 28 so that it can serve bothlgroups of elements 30 and 36. vAs illustrated, hcader 28 is connectedby flanges 4 O5- 4Q-to the mud ring 41 and to the beam 20 and has twointernal webs 42and 44 respectively which divide the header into threelongitudinal chambers. The forward chamber of header 28-is indicated onthe drawings by reference character 46, the central cham.

ben` by character 48 and the rear chamber by character 50. Chamber 46 isconnected through an. inlet-52 and by k.a ,-pipe not shown, to{theinterior of the boiler.Y Steam which has been introduced into thechamber 4(5passes thence into the` units 36 and back into the chamber48. From thechamber 48 steam fpasses into the units j30.and then backvinto the chamber -50 from which itymay be taken through an outlet 54j tothe engine throttle -by a pipe, not shown. Preferably the endsofgtheunits 80 and 36 are clamped toseatsjin the top wall o f header 28 bymeans of clamps `56, 56 and bolts 58, 58, bolts 58 extending downthrough the webs 42 and 44 below .the lower v face of the yheader 28 toprovide room for nutsl), 60. l

Arrangement shown inFigs. 4 and 5 is similar to/that shown in Fig. `lwith the eX- ception that the elements above the :arch brick areyarranged in y-a slightly different manner. In the formsfshown in Figs. 4

and y5, elements 30, 30 do not lie wholly in vertical planes, but arebent so .that their heat absorbing portions lie in a plane Vparallel, orsubstantially parallel, to the surface off-thc arch. They preferablyarecovered more or less by tiling 62 to .prevent them from receiving heatby convection, the elements 30` having van entirely-radiant. typecharacteristic when completely covered by ,A tiling 62. `IIowever, whendesired, a por- Itacte'd only slightly by the gases.

tion of the tiling 62 may be removed to eX- pose the upper surface ofthe elements 30', the tiling being formed in two parts 64 and 66 so thatupper parts may be removed for this purpose. Uncovering elements 30 byremoval of some of the-tile parts 66, however, doesv not greatlyalterjtthelradiant type heating characteristics of elements 30sincethese elements lie so close against the upper' surface of the'.arch thatltheyare'f'coii The upper and rearmost arch brick 34 in Figs.4-and 5 are of slightly different shape from the brick 34 topermit thetile parts 66 to be placed over the free ends of units 30. Similarly,the forward and lower jbrick26a-1of the arch shown inv Figs. 4 and 5 isspecially shaped to hold the tiling 62 in placef What I claim is: 'Y l.The combinationY in having arch tubes, of baffling on said tubes adaptedto radiateheat from itsupper sur. face and extending downwardlyV attherear of the lowerl ends of said-tubes, headers near the lower endsof'said tubes, and-supera tonelli fire-L52' heater elements 'arrangedalong theup.p er

and forward surfaceof said' baffling and having end portions runningdownvtofandconnected with saidhe2-1ders,4 said members4 all so arranged thatsaid, end-',portionsflie outside the current of combination .gas' es vV-2. Thecombination asset .forthin' l together with removable 4tilingover parts of the superheater elements.i

8.. The combinationpm .a boiler fire-'bok having arch tubes, of baiiiingmeans on said tubes, headers nearthelowerhends of said tubes and twosets-of. superheater units. having connections 4.with said,zheaders,lthe units of one of said sets arranged forward of said'headers and theunitsbfjthe .other of said sets arranged yabove saidbathing means.A I I4'. The'combinationas set forth in .cla-im l and inwhich the heatabsorbing .portions of the superheater elements lie-in parallel planes.y

' 5. f The combination asset Vforth in claim-1 and in which the-superheater elements arel bent so that` the heat absorbing portionslie" in thesameplane. c v

6. The combination as set :forth in claim l and in which thes'uperheater'elements are bent so that their heat absorbing por tions lie aplanesubstantially parallelto the baffling on the arch tubes. `z

7. 'The combination as set forthin claim 1 .togeth'er with fire wall inthe forward portion of the lireboxextendingnp .tothe level of thearchtubesatthefforward end,l

mouse low the level of the upper rear end of the baie.

9. The combination in a boiler fire boX having arch tubes, of baiiing onsaid tubes, superheater elements arranged along the upper surface ofsaid bathing, and headers for said elements near the lower ends of saidtubes to which the elements are connected, said baiing havingnon-metallic means separate from said elements and arranged to protectthe rear upper ends of said elements from direct impact of gases.V

10. The combination in a boiler fire box having arch tubes, of bafflingon said tubes adapted to radiate heat from its upper surface,super-heater elements arranged along the upper surface of said baiing,headers for said elements near the lower ends of said tubes and to whichthe elements are connected, said baiing having refractory means at itsrear upper end adapted to protect the rear ends of said elements fromdirect impact of gases and having means at its lower end adapted tosupport the longitudinal thrust of tiling carried on its upper surface.

HENRY B. OATLEY.

CERTIFICATE 0F CORRECTION.

Patent No. 1,905,739. April 25, 1933.

HENRY B. OATLEY.

1t is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 2,line 96, claim 1, for "combination" read combustion; and that the saidLetters Patent should be read with this correction therein that the samemay confbiltb lilzfecord of the case in the Patent Office.

` Signed andrsealed this 8th day ,of January, A, D.v 1935;

(Seal) Acting Commissioner oi Patents.

